Hyperlink Display problems in Word XP

Email addresses in my documents have normally been displayed in underlined blue type upon which you can double click to open a new Email message. When typing an Email address in a new Word document it automatically changed to underlined blue type

Suddenly my computer now displays Email Addresses in all old documents and in new ones in the form {HYPERLINK "mail to: [email protected]"}.

I have tried altering the Tools, Auto Correct and Auto Format settings with partial success - but cannot get back to the original set-up. I can now type an address and it is left as plain type - not the underlined blue as formerly. But old documents when opened in Word still show the word HYPERLINK etc.